1. Technical Field
This application relates to surgical instrumentation, and more particularly, to a surgical retractor having an expandable sheath which defines a retraction surface for manipulating tissue and organs during endoscopic or laparoscopic surgical procedures.
2. Description of Related Art
In conventional surgical procedures the function of holding tissue and organs in a given location to facilitate access and viewing is typically accomplished by a retractor. The instrumentation is typically in the form of a broad paddle structure or multiple fingers attached to a handle. See, for example, U.S. Pat. No. 3,467,079 to James. One disadvantage of these methods is the requirement of making large incisions, often through major muscles, in order to manipulate the above instrumentation in the body cavity.
Endoscopic or laparoscopic procedures overcome many of the drawbacks of conventional surgery. Such procedures are characterized by the provision of an elongated cannula structure having a relatively small diameter with a proximal and distal end. The distal end is passed through the surrounding tissue into a body cavity via an incision in the body wall. The body cavity is typically inflated or "insufflated" with carbon dioxide gas to aid in viewing and accessing the surgical site. The cannula provides a conduit for insertion of surgical instrumentation into the cavity. These procedures allow for smaller incisions, shorter patient recovery periods and require less anesthesia than conventional methods.
Although the insufflation gas expands the abdomen to permit the surgeon to view the surgical site, it is often necessary to manipulate the internal organs or tissues to provide a clear path to the surgical objective. In the prior art, it has been known to utilize grasping tools which pull on the organs or tissues to move them out of the way to provide a clear visual path for the surgeon. However, these devices may damage the organs or tissues which they grasp, and consequently these devices are utilized only when absolutely necessary. In order to avoid the problems associated with grasping tools, endoscopic retractor mechanisms have been developed which are utilized to push and hold the tissue or organs away from the surgical site. Typically, these devices include paddles and/or fingers which expand after the retractor has been inserted into the abdomen through the trocar cannula. Such devices are disclosed in, for example, U.S. Pat. No. 4,654,028 to Suma, U.S. Pat. No. 4,909,789 to Taguchi et al., and U.S. Pat. No. 5,195,505 to Josefsen. Other retractor devices include collapsible fingers joined by webs of resilient material which expand to form the retractor. These devices are disclosed in, for example, U.S. Pat. No. 4,190,042 to Sinnreich and U.S. Pat. No. 4,744,363 to Hasson. Other devices include retractors having expandable frames for supporting expandable latex sheaths or covers, such as that described in U.S. Pat. No. 5,178,133 to Pena.
While one or more of the aforementioned devices have been successfully used in laparoscopic procedures, larger organs, such as the intestine and/or stomach, tend to be too large and too heavy to be properly supported by these retractors. Consequently, the retractors have difficulty in clearing the surgical field to provide access for the surgeon to the surgical site. Due to the small size of the instrumentation, particularly the trocar cannula through which these instruments must pass, it is difficult to provide a retractor mechanism which can support or otherwise manipulate large and pliable organs such as the intestines or stomach.
Therefore, a need exists for a retractor mechanism which may be utilized to manipulate large organs and that is reliable as far as the strength and durability of the instrument is concerned. A need also exists for a retractor instrument that can clear the surgical site of heavy organs and tissue, where the instrument is small in relation to the organ and can be utilized with conventional trocar cannulas to provide access to the site during an endoscopic or laparoscopic surgical procedure.